This paper addresses the timing of a location’s historical transition from rural to urban activity. We test whether urbanization occurs sooner in places with higher agricultural potential and comparatively lower transport costs, using worldwide data that divide the earth’s surface at half-degree intervals into 62,290 cells. From an independent estimate of each cell’s rural and urban population history over the last 2,000 years, we identify the date at which each cell achieves various thresholds of urbanization. Controlling for unobserved heterogeneity across countries through fixed effects and using a variety of spatial econometric techniques, we find a robust association between earlier urbanization and agro-climatic suitability for cultivation, having seasonal frosts, better access to the ocean or navigable rivers, and lower elevation. These geographic correlations become smaller in magnitude as urbanization proceeds, and there is some variation in the effects across continents. Aggregating cells into countries, we show that an earlier urbanization date is associated with higher per capita income today.

Given a list of places you want to go, what is the shortest possible route that visits each place and returns to the place where you first started? This is the basic idea behind the Travelling Salesman Problem (TSP).

Most of us have faced this problem before, either when planning a trip with many cities/tourist attractions, or maybe when dealing with more complex stuff like optimizing public transport systems, air line operations, shipping routes etc. Computationally speaking, this used to be a difficult problem, but things are changing and the number of programs to solve the TSP is increasing.

Todd W. Schneider has created a brilliant code to build interactive solutions to the Traveling Salesman Problem using R and Shiny . In this post here, you may read in detail how the simulation process works and you may also play trying to find the shortest route through some world cities or through all of the US State capitals. (ht Tariq Khokhar).

Tuesday, September 16, 2014

Will the future of urban transportation look like this? I don't think so, but certainly I am not the best person to write about this topic.

If you are interested in how autonomous vehicles might change urban transportation, though, I would strongly recommend the reading of three pieces published in the Atlantic Cities (1, 2, 3). Also, you might like the work of Paul Newman and his collaborators at Oxford Mobile Robotics Group, which takes a more technical perspective.